Ruby: Access instance variable of parent object

Question

I have a set of objects that themselves each create a bunch of helper objects. Inside of the helper objects I need access to many of the parents instance variables, such as "name", a logger object and some more.

I could initialize the helper objects with all of the needed variables but that seems quite tedious. Is there a way to make the parents instance variables known to all the objects owned by it?

I have found a wealth of similar questions but most are about class variables and inheritance so I was not able to find a solution yet.

Example & rubyfiddle:

class Helper
  def initialize()
  end

  def complexStuff
    puts # Parent object name
  end
end

class Main
  attr_accessor :name

  def initialize( name )
    @name = name
    @helper = Helper.new
  end

  def update
    puts "[(#{name}).update]"
    @helper.complexStuff
  end
end

instance1 = Main.new( "Instance 1" )
instance2 = Main.new( "Instance 2" )

instance1.update
instance2.update

rubyfiddle

Nick Veys · Accepted Answer · 2014-03-28 15:23:53Z

2

Why not just pass the parent in?

class Helper
  def initialize(parent)
    @parent = parent
  end

  def complexStuff
    puts @parent.name # Parent object name
  end
end

class Main
  attr_accessor :name

  def initialize( name )
    @name = name
    @helper = Helper.new(self)
  end

  def update
    puts "[(#{name}).update]"
    @helper.complexStuff
  end
end

instance1 = Main.new( "Instance 1" )
instance2 = Main.new( "Instance 2" )

instance1.update
instance2.update

answered Mar 28, 2014 at 15:23

Nick Veys

24k5 gold badges49 silver badges66 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Ruby: Access instance variable of parent object

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related